A 5-year-old patient received Pentacel (DTaP-IPV/Hib) for the 5th dose of DTaP instead of Quadracel (DTaP-IPV). Can I count the Pentacel as a valid dose or will we need to revaccinate this patient?

While administration of Pentacel to a 5-year-old would be considered off-label and a vaccine administration error, the doses of DTaP and IPV can be counted as valid and do not need to be repeated. Hib vaccine is not routinely administered after a child has reached the age of 5 years so it is also a vaccine administration error. You should explain this error to the parents and assure them that the extra Hib dose will cause no harm.